The present invention relates to a drain cleaning machine, and more particularly to a release assembly for removing the rotatable drum from the machine without tools.
Conventional drum type drain cleaning machines typically include a frame structure supporting a rotatable snake drum and a drive motor arrangement for rotating the drum. The frame structure also supports a snake feeding arrangement by which the snake or cable is axially displaced relative to the rotating drum during use of the machine. The snake coiled within the rotatable drum is displaced by the feeding arrangement and inserted into a pipe or drain to be cleaned. Rotation of the drum rotates the snake to achieve such cleaning.
The rotatable drum in known drain cleaning machines may typically be removed from the support frame and drive arrangement to facilitate replacement of the drum with one containing a snake having a different diameter and to make the separate components more mobile. Disadvantageously, conventional removable drums require tools to disassemble the rotatable drum from the support frame. This, of course, requires access to the proper tools and is also somewhat time consuming for the operator. Other known disassembly arrangements require a groove cut in a shaft which mounts the rotatable drum. The groove is located between the rotatable drum and the support frame to receive a spring loaded pin which rides within the groove. The groove is retracted to disassemble the rotatable drum from the support frame. By its location, the groove reduces the strength of the shaft in a weight bearing segment. Friction between the groove and the single pin may also eventually require the repair or replacement of the disassembly arrangement. Further, the pin must be manually retracted to both install and remove the rotatable drum.
Accordingly, it is desirable to provide a rotatable drum release assembly which provides an effective release without the necessity of tools and which locates shaft grooves in a position to minimize their load bearing effect on the shaft. It is further desirable to provide a rotatable drum release assembly that need not be manually actuated to assemble the rotatable drum to the support frame.
The rotary drum release assembly according to the present invention provides a multiple of lock pins which engage a drum shaft to lock and unlock a rotary drum to a drain cleaning machine. The rotary drum release assembly is mounted within a support frame assembly. The drum shaft extends from a sleeve in a cantilevered manner and the shaft groove is located within the sleeve to minimize localized weakening of the shaft.
The rotary drum release assembly includes a fixed cylindrical member mounted to the support frame about the sleeve. A pair of apertures extend through a wall of the fixed cylindrical member and are aligned with a corresponding pair of square openings which pass through the sleeve. The openings are located substantially perpendicular to the rotational axis of the drum shaft. The lock pins are mounted through the square openings and biased toward a groove in the rotary drum shaft.
Rotation of an actuating handle engages cam surfaces with cam pins extending from each of the lock pins to overcome the bias of the lock pins and simultaneously drive the lock pins away from the shaft. Once the lock pins clear the groove the drum shaft may be pulled from the sleeve. The drum is thus released. Releasing the actuating handle allows the handle to fall to its locked position.
To mount the drum, the drum shaft is pushed into the sleeve. As the distal end of the shaft is substantially conical, the distal end pushes the lock pins out of the way as the shaft is pushed into the sleeve. Once the shaft groove is aligned with the lock pins, the lock pins are driven toward the shaft by the springs such that the distal ends of the square portion are received into the shaft groove. The drum shaft is thereby rotatably locked into the sleeve.
The present invention therefore provides a rotatable drum release assembly which provides an effective release without the necessity of tools and which locates shaft grooves in a position to minimize their load bearing effect on the shaft. The present invention further provides a rotatable drum release assembly that need not be manually actuated to assemble the rotatable drum to the support frame.